Implantation depth and prosthesis oversizing contribute to conduction abnormalities (CA) and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR).
Researchers noted that after replacement with next-generation balloon-expandable valves, new or worsened CA, particularly complete left bundle branch block (LBBB), and PPI has been reported between 8% to 30% and 5 to 12%, respectively.
In total, 244 patients were treated with the SAPIEN 3 valve (Edwards Lifesciences; Irvine, CA). Of those 244 patients, 208 were eligible for PPI analysis (patients with previous pacemakers, atypical valvular anatomy, or degenerated biological prostheses were excluded). Of those 208 patients, 184 were evaluated for new CA or PPI (patients with complete bundle branch blocks at baseline were excluded).
New PPI and new or worsened CA or PPI occurred in 16% (34 of 208 patients) and 31% (57 of 184 patients), respectively.
Implantation depth, calculated as percentage of frame height below aortic annulus, was examined in 207 patients (mean implantation depth: 26% ± 7%; range 6% to 48%). In terms of prosthesis sizing, 77% of patients were within range, 12% were undersized, and 11% were oversized.
Patients who required PPI had higher prevalence of atrial fibrillation (44% vs 24%; P=.017), complete right bundle branch block (RBBB; 27% vs 5%; P=.001), and bradycardia (<60 beats/minute; 38% vs 21%; P=.034). There was also a trend toward deeper implantation in these patients, particularly at the non-septal side.
“A deeper positioning of the prosthesis below the aortic annulus might cause CA via mechanical stress and direct damage of the conduction system,” researchers noted. “The present study extends these findings to the SAPIEN 3 valve, showing depth of implantation as an independent predictor of new or worsened CA or PPI. The SAPIEN 3 valve possesses a higher frame and extends deep into the left ventricular outflow tract.”
Emerging figures place incidence of PPI after TAVR with the SAPIEN 3 valve between 13% and 25.5%. There may be other reasons for higher rates in PPI, aside from device-related issues, such as pre-existing RBBB.
Researchers urged future studies to examine what factors may decrease PPI and new or worsened CA, such as higher implantation position and/or avoidance of prosthesis oversizing.
Husser O, Pellegrini C, Kessler T, et al. Predictors of permanent pacemaker implantations and new-onset conduction abnormalities with the SAPIEN 3 balloon-expandable transcatheter heart valve. JACC Cardiovasc Interv. 2016;9(3):244-254. doi: 10.1016/j.jcin.2015.09.036.